Wheel arch liners are installed in vehicle wheel wells, underneath the fenders, and from the perspective of a viewer looking at a wheel well are located up above and extend back behind the wheel. Wheel arch liners serve two primary functions: First, they chiefly protect the interior of a vehicle's body and proximate components from exposure to high speed dirt, debris, and road hazards that may be picked up and flung by the wheel of a vehicle while in motion. Similarly, a wheel arch liner can serve to contain tire fragments in the event of a blowout. Without a wheel arch liner, such debris at best would create annoyingly loud impact sounds as metallic or hard plastic vehicle body components were struck by solid debris, or at worst would damage vehicle body components, potentially with dangerous results. Second, wheel arch liners can act as a first-line sound barrier to absorb wheel and road noise, and prevent it from being transmitted to the vehicle's cabin.
Known wheel arch liners are not entirely satisfactory for the range of applications in which they are employed. For example, existing wheel arch liners are commonly manufactured from a plastic such as polypropylene or high-density polyethylene, and formed using an injection molding process. Injection molded polypropylene wheel arch liners are typically used, as they have established good performance characteristics in wheel arch applications. Furthermore, for large batch quantities, injection molding offers an attractively low per part production cost, and with an appropriately designed mold, the ability to have continuously varying material thicknesses or even densities to provide additional structural reinforcement and rigidity in places most likely to receive wear from road debris. However, the injection molding process first requires the creation of a tooling for production, specifically, a custom mold in the shape of the wheel arch liner compatible with the injection molding equipment intended to be used for production. The creation of such custom tooling imposes a significant initial cost, and consequently is best suited only for those times when a high volume of part production is anticipated. Conversely, for small job runs or one-offs, such as in the case of limited run vehicles, injection molding proves impractical as it imposes a significant financial strain on a project's budget.
Thermoformable textile materials can possess durability comparable to injection molded polypropylene, and can often be used in manufacture at a cost lower than injection molded polypropylene. However, textile materials heretofore have lacked adequate rigidity and stiffness to be employed in wheel arch liner applications, where a durable rigidity is required. Moreover, textiles typically come in a single thickness, and thus present a challenge where additional structural rigidity is required in only certain areas.
Hot-molding is a known technique where materials for an object are placed into a mold, and then the mold is closed and heated so as to cause the materials within to take on and retain the shape of the mold. The production of such molds and heating not constrained to particular types of equipment, such as an injection molding machine. Consequently, hot-molding presents a possible alternative to injection molding for parts formation. German Patent Application Publication No. DE102010049598 A1 (the “598 publication” is directed to a liner for a wheel arch that is formed as a molded part. The 598 publication discloses using a composite or possible textile material in a hot mold, but still uses a partially injected area around the edge of the arch to provide enhanced wear resistance.
Thus, there exists a need for wheel arch liners that improve upon and advance the design of known wheel arch liners. Examples of new and useful wheel arch liners relevant to the needs existing in the field are discussed below.